[lld] [llvm] [lld][AArch64][Build Attributes] Add support for AArch64 Build Attributes (PR #147970)

[Fangrui Song via llvm-commits]

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@@ -775,6 +807,28 @@ void ObjFile<ELFT>::initializeSections(bool ignoreComdats,
       continue;
     }
 
+    // Extract Build Attributes section contents into aarch64BAsubSections.
+    // Input objects may contain both build Build Attributes and GNU
+    // properties. We delay processing Build Attributes until we have finished
+    // reading all sections so that we can check that these are consistent.
+    //
+    // Ideally this belongs in the following switch, but due to the
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MaskRay wrote:

I'd remove "Ideally this belongs in the following switch, but due to the" and change the comment order:

```
// Processor-specific types that do not use the following switch statement.

// Extract Build Attributes section contents. Input objects may contain both build Build Attributes and GNU ...
```

https://github.com/llvm/llvm-project/pull/147970